Light decides it: in bright indirect light the white spathes keep coming; in a dim corner the plant stays green.
The peace lily is the plant that tells you exactly what it wants: when it is thirsty the whole plant wilts dramatically, and within hours of a drink it stands back up as if nothing happened. That honesty, plus a tolerance for low light most flowering plants can't match, makes it a genuine beginner's plant.
The white 'flowers' are actually spathes - modified leaves wrapped around a slender spike - and it produces them most freely in medium light with steady moisture and humidity. Brown leaf edges point to dry air, tap-water salts, or overfeeding. Give it a warm, draught-free spot and it will bloom on and off through the year.
Happy in low to medium indirect light - one of the few that flowers away from a bright window. Too much direct sun scorches the leaves; too little light and it simply stops blooming.
Water when the leaves start to droop; it bounces back fast
Feed lightly with a balanced fertiliser
Wipe the broad leaves to keep them glossy
Brown leaf tips mean dry air, salts, or overfeeding
Divide and repot when the clump crowds the pot